Belt tightener



J. w. HoMl-:R

BELT TIGHT-ENER March 14, 1933.

2 Sheets-Sheet l Filed Aug. 9, .1930

Patented Mar. 114, 1933 y UNTTED STATES PATENT oFFicE JOHN W. HOMER, orGREENCASTLE, PENSYLVANIA, essIGNoR To T. B. Woons soNs COMPANY, oFoBAMnERsBURG, PENNsYLvANTA p i BELT TIGHTENER A pplicationled August 9,1930. vSerial No. 474,251'.

My invention relates to belt tightners in insertionl inand to be clampedby the brackwhich there is a pivoted` arm carrying a et bearing. The`boss13 has an integralad-` pulley for engaging the slack reach of abeltjustlng extension ,for the reception `tof a" to tighten it. v vwrench, and shown 'of heXa on shape at'14.

The object of the invention is to produce This plate 12 has on itstacetwo spaced '55 a simple, readily made device'of thisftype, stops 15andlG., p' f in which the whole mechanism can be easily Journalled intheV plate member and pretv adjusted, angularly, with respect toitssuperablypassing-entirely through the same is port, standardor'bracket, and will. be opa shaft'l?. One end oi' the "shaft `has a:

l erable in any such adjusted position. washer 18, and yis secured inthemember by 60 l" The pulley-carrying arm shall" engage a a Cotter 19.`The other end of the shaft has lever at each side thereof, with springmeans secured to it the arm that carries a pulley for said arms to urgelthelevers against stop shaft 21 on V,which is journalledr the beltmeansand to urge the pulley-carrying arm tightening pulley 22.y Y y 15 to itsmiddle position when deviated there- Projecting from the rear of the arm20 are 65 froml to opposite sides of this middle potwo spaced stops 23and 24. Y l Sitiom Y Y J ournalled on the shaft 17 between the Otherdetails of construction will be here# pulley arm 20 and the plate 12:are two leinafter more particularlyk described and vers and 26. Thelever 25 is provided 2o Claimed A v with an extension.. 28 .normallyresting 70k Referring to the drawings, in which likel against the stop1,6 and movable toward and parts are similarly designatedagainst theopposite lug15, while the other Figure 1 is a front view of a belttightener, lever 26 has a similar extension 27normallyV embodying myinvention, with the belt con- I'esting against the lug- 15 and movablepast 25 tacting pulley shownionly in dotted lines. extension 28 towardand against lug 16.` 75 l Fig. 2 is a side elevation. Y The'two levers25 and26 are identical but Fig. 3 is an elevation of the rear end ofreversed, so that but one casting hasto .be

the main casting, or plate member. made for these levers, asvwillbe seenfromH Fig. 4 is a front elevation of a modicathe drawings. These klevershave` lugs 29 levers. 23 and 24 on the back of the pulley arm 20. Fig. 5isa side view, and Y Each lever arm is provided `near its one Fig. 6 isan elevation of a modification end with a screw-eye 31 and alock-nut'32, using a compression and a tensionk spring and the ends of acoiled extensionk spring o0 tion where but a single stop isusedvfor theand 30 that. respectively abut against the lugs 80- for the levers. 33are hooked in or otherwisepfastened to 85 i Fig. 7 is an elevation, andthe screw eyes. v Fig. 8 is a side view of a further moditica- Theoperationv ofV the structure labove de? tion in which two tensionsprings are used.` scribed is as follows:

Fig. 9 is a detail of a detent for holding The standardl 10 beingmounted in proper the belt tightener in adjusted position. position atthe side of the belt. to be tight- 90V Referring to Figures 1-3, I haveshown ened, the screw 11'is slightly 'loosened toala standard 1()provided with split bearing low the boss 13 to be inserted in thebearing at the top and clamped together by a screw of the bracket 10,-with the pulley resting 11 that frictionally holds a main casting orlightly against the slack side of thenbelt. plate member. Any form ofstandard, or A wrench isthen applied tothe hexagonal 95 any other meansto stationarily hold this boss extension 14, andthe plate member withmember in adjusted angular position may its assembly ofv pulley, pulleyarm, and be used. spring lever arms isforcibly revolved in the Thismember consists of a plate 12 having bearing of the bracket 10 againstthe preson its back a cylindrical bearing boss-13 for sure ofgthe belt,thus bringing intoaction 100 one of the lever arms 25 or 26, which isdis placed from its stop or 16, against the spring tension while thepulley is forced against the slack side of Vthe belt. When suiicienttension is exerted the boss 13 is locked in position by tightening thescrew 11.

As the belt lengthens and shortens under load the pulley arm 2O swingsin accordance with the amount of slackness of the belt taken up by thelevers'25 or 26 under the tension of the spring y33.

If the pulley arm swings beyond its normal position, one of the levers,or 26'will yieldingly resist the movement until it is positively stoppedby striking its extension 27 or 28 against its stop 15 or v16. VThepulley yarm is resisted or damped in both directionstoward and from thebelt.

The structure -is such that 4it may be mounted near either edge of thebelt or against either the inner or outer face of the belt Withoutalteration of the construction.

In Fig. 4 asimilar construction is shown, but in this form the two stops15 and 16 and the lever extensions 27 and -28 are omitted, and in lieuof them is a single stop 34 on the plate 12 that projects between thelevers 35 and 36 against which one of them strikes to prevent it frommoving with the arm when the other lever is moved against the pull ofthe coil spring 33 by the pulley arm.

Instead of the lugs 29 and 30 integral withthe levers, I may useVadjustable lugs in the form of set-screws, Fig. 4.l

When stronger resistances are in question, in lieu of using a pluralityof coil springs between the screw eyes at one end only of the levers, Iprefer to place a coil spring at each end of the levers, and this typeof belt tightener is illustrated inFigs. 5 to 8.

. I' have shown a bracket 38 in which the plate member has bearing. Theplate 12 has a stop 34 between the levers 39 and` 40.y

Each of these levers has laterally projecting lugs 41 and 42 forengagement with the lugs 23, 24 on the pulley arm 20; and each lever hasan extension arm 43 beyond the pivot shaft 17. One of these arms isVprovided with a pin 44 on which one end of a compressionspring 45 seats,and the other end of this spring engages an adjustable seat. 43a in theother extension arm v43.

The compression spring 45 urges the extensions 43 apart while theopposite ends of the levers 39, 40 are urged toward one another,assisted by the springs 33.

In `this construction the plate 12 is provided with spiral teeth 46 onits periphery and forms a worm wheel with which meshes a worm 47 mountedin ears 48 on the standard or bracket 38. The worm is provided with ahead 49 for applying a wrench for turning the worm and by it the plate12, to angularly adjust the mechanism in the standard or bracket.

In Figs. 7 and 8 the lever extensions 50 and 51 cross one another, withthe result that the coil spring 52 is a tension spring, the same asspring 33.

The plate member is, as above stated, frictionally held in its splitbearing, which is sufficient for small constructions of beltVtighteners, but in the larger constructions I provide a positive detent,which is provided by the worm and Worm 'wheel'construction `Another formof simple, positive detent is illustrated in F ig. 9, where the plate 12is provided with ratchet teeth 53 and is engaged by a pawl 54 mounted ona pivot 55 on the standard or bracket. The pawl has two teeth engagingends 56 and 57. This pawl willact as Va detent for the `plate 12 in yeither direction of angular slip. All that is necessary is to move thepawl 54 on its pivot,

so that tooth 56 will cooperatey with the ratchet teeth 53.

yI claim- 1 1. A'belt tightener comprising an angularl-y adjustableplate member, a'pulle'y arm v pivoted to the member, pivotedleversengagingfopposite sides of-'said arm,spring means urging thelevers against the arm and stop means to detain rone lever when theother lever is deflected by the arm.`

- .12. yA ibelt. tightener comprising an angularly adjustable Vplatemember, a shaft jour-y nalled therein, a pulley arm secured tothe shaft,two'levers pivoted on the shaft between the member and arm and arrangedto engage the arm, each lever having an extension,'a spring'connectingthe levers together, means comprising a vpair of spaced stops on themember for engaging said extensions to selectively detain one lever andvEl() limit themovement ofthe other lever under the action of said arm.K

3. A belt tightener comprising an angularly adjustablevplate member, ashaft journalled therein, a pulley arm xed to the shaft, two leversloose on the shaft between said member and arm and which engage theopposite sides -of thevarm, two spaced stops on vsaid member, anextension on' each lever, both extensions projectingbetween the stopsone disposed against va stop and the T54 movement of the otherlimited bysaid stop.

4. A belt tightener-comprising a standard having'a split bearing andascrew'to clamp the same, a plate member having a plate, a

bearing boss and an adjusting extension,

a shafty journalled in said member, two

spaced stops on the plate, a pulley 'arm sellt) two levers pivoted onthe shaft between said plate and arm, adjustable lugs in the levers forengaging the Vopposite sides of said arm, a stop on the member extendingY between the levers and a spring to urge the levers toward the arm.

6. In a belt tightener, an angularly adjustable plate member, a shaftjournalled therein, a pulley arm secured to said shaft, two leverspivoted on the shaft and contacting with the arm on its opposite sides,a stop on the member between the levers, a spring between the levers,extensions on the opposite ends of the levers and a second springbetween the extensions, both springs urging the levers to the stop andpulley arm.

7. In a belt tightener, an angularly adjustable plate member, a shaftjournalled therein, a pulley arm secured to said shaft, two leverspivoted on the shaft and contacting with the arm on its opposite sides,a stop on the member between the levers, a spring between the ends ofsaid levers, crossed extensions on the opposite ends of the levers and asecond spring between the extensions, both springs urging the levers tothe stop and pulley arm.

8. In a belt tightener a standard, an angularly adjustable plate membercomprising a circular plate having teeth on its periphery, a boss on oneface for adjustably holding the member in the standard; a shaftjournalled in the member, a pulley arm on one end of the shaft, atightener pulley on the arm, means on the standard engaging the teeth toangularly adjust the circular plate in the standard, a pair of leversloose on the shaft engaging opposite sides of the arm to damp themovement of the arm in either direction, spring means connecting thelevers and stop means for the levers to stop one lever as the otherlever is moved by said arm. ,y

9. In a belt tightener, a support, an angularly adjustable membercarried by Said support, means for angularly adjusting said member withrespect to said support, means for locking said member in adjustedposition, a pair of levers, means for pivotally supporting said leversadjacentl said member, means on said member for engaging one of saidlevers to rotate said lever as said member is angularly adjusted,resilient means connecting said levers, a pivotally fsupported arm,having a pulley secured thereto spaced from the pivot of said arm, andan abutment Xedly associated with said arm in position to be engaged bythe other of said levers.

l0. In a belt tightener, a support, an angularly adjustable membercarried by said support, means for angularly adjusting said member withrespect to said su port, means for holding said member in a justedposition, a pair of levers, a pivotal support for

